I need a straight answer....
VIP Member
01-26-2008, 06:29 PM
#22
Registered
hey Chuck did you evertalk to David Wade? He still has that cig that was wrecked, I saw it today. Its got 525`s in it. I dont know if that exaust will fit on your motors or not.
01-27-2008, 12:04 AM
#24
Platinum Member
Platinum Member
Join Date: Oct 2003
Location: Townsville Australia
Posts: 778
Likes: 0
Received 0 Likes
on
0 Posts
Rotax you have it wrong.Lets start by saying i do all my own motors,race and pleasure.Why are most Mercruisers fitted with them?Because thats how the motors come from GM.I doubt theres another reason.Just because you have a crossover(nice shiny piece of stainless that doesn't corrode,break,have bearings or bushes,take hp)water temps can still be kept constant.You still run a thermostat and if you really want to dial in a precise temp setting at any given speed/rpm,drill a 3/16 hole in the outer of the thermostat body.If you still need it cooler drill another.Then there's all the hoses that aren't needed .What about that factory thermostat housing,made to corrode.It too gets replaced with a nice piece of stainless.Every raw water cooled marine engine can benefit from a crossover.
01-27-2008, 06:38 AM
#25
Registered
iTrader: (2)
That statement is true, and for good reason. That motor has a specific design/purpose-----racing. Take for example a performance boater with an HP525efi motor. That motor see's WOT to idle. It needs a consistent to short tolerance range of water temps (oil too). That can only be accomplished properly by using a recir pump and t-stat.
Example of why using a crossover (on many, not all cases) has it's problems: Your running at WOT and the water temps are just fine. Then you pull back on the stick/sticks and bring the motor back to idle. Watch the water temp gage fall in the basement. There goes your consistency. An open invitation to the possibility of condensation. My .02
Example of why using a crossover (on many, not all cases) has it's problems: Your running at WOT and the water temps are just fine. Then you pull back on the stick/sticks and bring the motor back to idle. Watch the water temp gage fall in the basement. There goes your consistency. An open invitation to the possibility of condensation. My .02
ok..
i kinda wish i would have went with a closed cooling myself.. seeing what you did makes sense. wonder if i should do mine like that..
01-27-2008, 09:18 AM
#27
Pirate of the Chesapeake
Gold Member
iTrader: (2)
Join Date: Aug 2006
Location: North Point Creek, Md.
Posts: 4,330
Likes: 0
Received 0 Likes
on
0 Posts
Pumps
Let's face it merc puts pumps on their motors so they know that from the factory it is running a consistent temp.So if they have a warrenty problem they can say you ran it to hot, to cold .And they know it was from circ. pump or stuck stat,or no stat. If they put crossovers on them they would never know at what temps the engine was running,beacaus of boats being in different water temp area's.And they also put them on their to make their product almost IDIOT proof!!!! I built lot's of motors and never ran a pump. Used a external bleed off on big blocks so they wouldn't run to cool and milk up the oil,or a washer in the stat housing to slow down the water.Also you have one less belt to jump off at WOT runs. That's what I think. Might be wrong!!!!! JOHN
01-27-2008, 10:54 AM
#28
Registered
Thread Starter
Join Date: Aug 2004
Location: The Swamps of La.
Posts: 1,410
Likes: 0
Received 0 Likes
on
0 Posts
I see that this issue is like asking "Who makes the best hull?"
I do 95% of my running in Lake Pontchartrain, which in the summer is never below 75 degrees. I do like the way the xover dresses up the engines and once it is dialled in it looks like it's not something you have to worry about any longer.
Thanks for all the replies gentlemen.
Chuck
I do 95% of my running in Lake Pontchartrain, which in the summer is never below 75 degrees. I do like the way the xover dresses up the engines and once it is dialled in it looks like it's not something you have to worry about any longer.
Thanks for all the replies gentlemen.
Chuck
